Often there is a need to add client-side Javascript to the ASP.NET page from server-side code. To perform additional manipulation on rendered controls (hide or disable), to show user an alert message – just a couple of examples. Standard ASP.NET approach is to use page’s client script manager’s  RegisterStartupScript method:

Me.ClientScript.RegisterStartupScript (Type,  Key,  Script, AddScriptTags)

Where

type: The type of the startup script to register.
key: The key of the startup script to register.
script: The startup script literal to register.
addScriptTags: A Boolean value indicating whether to add script tags.

For example:

Me.ClientScript.RegisterStartupScript (Me.GetType(), "alert", "alert('Hello world!');", True)

But if you’re using Infragistics controls that offer async postbacks, like WARP panel or UltraWebTab – there is a problem with this approach.  Since the page doesn’t go through the full postback and doesn’t get destroyed and re-rendered from scratch – this method doesn’t work. Continue reading →